WIP: use arrow-wasm instead of custom rust library for tests

[kylebarron]

Right now, arrow-js-ffi uses a custom Rust module for tests. I'm trying to build out arrow-wasm as a core library for Arrow in wasm, and so it would be great to use that directly instead of a custom module.

It works except for accessing individual columns, which isn't currently supported/fleshed out in arrow-wasm

Note: to build inside the arrow-wasm submodule, I ran:

wasm-pack build --target nodejs --out-dir pkg_arrow1 --out-name arrow1 --features arrow1 --features console_error_panic_hook
wasm-pack build --target nodejs --out-dir pkg_arrow2 --out-name arrow2 --features arrow2 --features console_error_panic_hook